Photoelectrostatic copying machine



Aug. 20, 1968 .1. v. BRUNING ET AI- 3,397,627

PHOTOELECTROSTATIC COPYING MACHINE Filed May 2l, 1965 7 Sheets-Sheet l J. v. BRUNING ET AL 3,397,627

PHOTOELECTROSTATIC COPYING MACHINE Aug. 20, 1968 v sheets-sheet 2- F'iled May 21, 1965 Aug. 20, 1968 J. v. BRUNING ET AL PHOTOELECTROSTATIC COPYING MACHINE '7 Sheets-Sheet 5 Filed May 2l, 1965 Aug. 20,1968 J. v. BRUNING ET AL l 3,397,627l

PHOTOELECTROSTAT IC COPYING MACHINE Filed May 21, 1965 '7 Sheets-Sheet 4 Aug. 20, 1968 .1. v. BRUNIING ET Al- 3,397,627

PHOTOELECTROSTATIC www@ MACHINE Filed Mayzl 1965 7 sheets-Sheet 5 Aug. 20, -1968 Filed May 21. 1965 J. V. BRUNING ET AL PHOTOELECTROSTATIC COPYING MACHINE '7 Sheets-Sheet 6 Aug. 20, 1968 J. v. BRUNlNG ET AL 3,397,627

PHOTOELECTROSTATIC COPYING MACHINE Filed May 21, 1965 '7 Sheets-Sheet 7 260 4^ ggb 1A51.; M2011 l www 15g C 29PM i gga ma swam m l j@ UnitedA States Patent O 3,397,627 PHOTOELECTROSTATIC COPYING MACHINE John V. Bruning and Robert C. Patzke, Prospect Heights,

William A. Ghiselli, Jr., Des Plaines, and John L. Tregay, Wilmette, Ill., assignors to Addressograph- Multigraph Corporation, Mount Prospect, Ill., a corporation of Delaware Filed May 21, 1965, Ser. No. 457,649 19 Claims. (Cl. 95-1.7)

ABSTRACT OF THE DISCLOSURE An apparatus for making copies of a graphic original which is placed face down on the top wall of the apparatus on a transparent glass platen so that it can be illuminated by incandescent light sources within the apparatus. A source of copy sheets is provided from which are automatically fed sheets past a charging station and are carried on a belt conveyor system to an exposure station. Arrival of the charged copy sheet at the exposure station energizes the illuminating means for a given period of time after which the conveyor is reactivated to deliver the exposed copy sheet to the developing station. An adjustable optical system is provided permitting a 1:1 size image projection or a reduced image to be projected. A separate, independently driven, conveyor system rapidly delivers the copy from the developer to a location outside the apparatus adjacent the transparent platen.

This invention relates to a copying apparatus and, more particularly, to a new and improved photoelectrostatic reproducing apparatus.

The technology of making copies of a graphic original electrostatically involves the application of a uniform electrostatic charge in thedark to a photoconductive surface selectively discharging the surface by exposure to a pattern of light and shadow in accordance with the original being copied to provide a latent electrostatic image, and rendering the latent image visible by applying finely divided electroscopic particles. The latent image can be developed directly on a photoconductive copy sheet or on another surface from which the'visible image is subsequently transferred to a plain sheet. A Wide range of apparatus is available to carry out the foregoing operations. They provide for the synchronous relative movement of a graphic original to the moving charged photoconductive surface during the exposure step in which the latent charge image is formed. In other prior machines, the original is held in a fixed position and a corresponding light pattern produced by light scanning the fixed original in synchronism with the moving charged surface. These copying machines, operating on the principle of transporting the original and/or the sheet on which the copy is produced, enjoy the advantage of high rate copy output since the operational steps are carried out while the elements are in motion. The mechanisms required for these synchronous movements and transporting assemblies are complex and of precision construction increasing not only the initial cost but the cost of maintenance. The optical systems employed must be carefully controlled so that the machines are capable of only a fixed size relative to the original.

Accordingly, one object of the present invention is to provide a new and improved photoelectrostatic copying machine.

Another object is to provide a photoelectrostatic copying machine of a compact and economically fabricated construction.

Another object is to provide a copying machine in which van image of a stationary object is projected onto a stationary copy sheet.

3,397,627 Patented Aug. 20, 1968 r: ICC

A further object is to provide a photoelectrostatic copying machine including new and improved sheet conveying means.

A further object is to provide a photoelectrostatic copying machine including an intermittently operating copy sheet conveying means for moving a copy sheet to an exposing station in which it is held in a stationary position during exposure, the conveying means then being placed in operation to feed the exposed copy sheet to a developing station.

A further object is to provide a photoelectrostatic copying machine in which the area for receiving the subject to be copied, the copy delivery station and the copy sheet feed station are all accessible at or near the top of the machine.

A further object is to provide a copying machine in which the air intake to and the air discharged from an air impelling means are used to mount flexible material on a conveying means at spaced points in the path of movement of the liexible material.

Another object is to provide a copying machine including new and improved means for easily changing the size of copies produced by the machine by simple manual adjustments that can be made externally of the machine by its operator.

A further object is to -provide a copying machine including novel means for changing the copy size by varying the relative positions of components of the optical system provided in the machine.

A further object is to provide a copying machine including new and improved means for feeding copy sheets.

Another object is to provide a new and improved assembly for feeding sheets of flexible material.

In accordance with these and many other objects, an embodiment of the invention comprises a photoelectrostatic copying machine adapted to be mounted on a desk or table and having a somewhat rectangular housing with a generally uniplanar upper surface. An illuminating station is provided at one end of the housing and includes a light transmitting or transparent glass plate forming a part of the top Wall structure and having an edge coextensive with an edge of the housing. This permits not only sheets of original material but also pages from bound volumes to be copied by placing the page to be copied on the glass plate with the remainder of the book disposed along the side of the housing. Suitable illuminating means for directing light on the transparent member provide a reflected light image which is supplied through an optical system including a reflecting assembly and a lens assembly to an exposure station disposed in a fixed plane. By manually adjusting the relative positions of the lens assembly and the reflecting assembly relative to each other and to the fixed exposure plane from a control located external of the machine, the original can be copied in different selected sizes.

To supply a copy sheet of the phot-oelectrostatic type to the exposure station, the copying machine includes a copy sheet feeding assembly mounted immediately adjacen-t but just lbelow the top wall surface of the housing, the housing being provided with a removable cover to permit the insertion of copy sheets on a stack supporting table or tray forming a part of the sheet feeding assembly. This assembly includes driven sheet engaging rollers carried on pivotally mounted lever means which are normally biased Iby resilient means to a position in which the drive rollers are spaced from the stack, When a copy is to be produced', a solenoid is energized to retract an armature which is connected by flexible connecting means including a resilient means to the lever. The retraction of the armature pivots the lever 'against its resilient Ibias to move the rollers against the top sheet in the stack to feed this sheet out of the feeding assembly and into a guideway incl-uding a pair of driven rollers. The solenoid is then released, and the separated sheet is fed in the generally horizontal direction into a curved guideway into w-hich a switch operator arm projects. When the leading edge of the sheet engages the switch operator to actuate the switch, a coro-na charging unit including a generally vertically extending sheet passageway is energized so that as the sheet is advanced iby the driven rollers, uniform electrostatic charges 'of opposite polarities are applied to both sides of the copy sheet.

An intermittently operated lirst sheet conveying or transporting assembly, which forms a part of the exposure station, receives the charged sheet discharged from the corona unit. This conveying means includes a plurality of spaced exible belts or closed loops which form vone side of a duct structure or plenum chamber connected to the intake of an air impelling means. Thus, when the leading edge =of the charged sheet is discharged from the charging station int-o proximity to the first sheet conveying means, the sheet is held against the exible belts by the negative pressure induced across the belts by the air impelling means. The conveying belts extract the charged copy sheet lfrom the charging station and advance it in a generally downwardly extending direction to an exposure position in which it is disposed in the xed exposure plane. At this time, the leading edge lof the sheet engages a switch operator projecting into the path of movement of the first sheet conveying means. When this switch is actuated Iby engagement of the switch operator, the first conveying means is rendered inoperative, and the charged copy sheet is held in a stationary predetermined position. The actuation of this switching means also causes the momentary energizati-on of the illuminating means so that a light image representing the original material to be copied is forwarded through the optical assembly tose lectively discharge the illuminated surface of the copy sheet to provide a latent charge image representing the original to be copied.

After a predetermined time delay, the first sheet conveying means is again placed in operation to advance the exposed copy sheet to a developing station including a tank iilled with a liquid developer comprising electroscopic powder and a liquid carrier. This developer station includes a guide struc-ture with an inlet disposed immediately beneath the discharge of the first conveying means and an outlet or exit disposed immediately beneath the inlet of a generally vertically extending discharge conveying and drying means. Thus, when the first conveying means is placed in operation, the exposed copy sheet is fed through the liquid in the devel-oper tank to permit the selective deposition of electroscopic powder on the exposed surface of the sheet in accordance with the electrostatic image. This selective adherence or deposition of electroscopic material converts the latent electrostatic image into a visible image.

The discharge conveying and drying means comp-rises a plurality of flexible belts disposed in spaced apart relation and extending, in a generally vertical direction parallel to and spaced to one side of the rst conveying means. A louvered duct or chamber connected to the discharge side of the air impelling means is spaced from the tiexible belts so that the air discharged from the impelling means is directed against the outer surface of the belts. Thus, when the leading edge of the developed copy s-heet leaves the exit opening in the developer tank, this leading edge passes between a pair of driven rollers to be advanced to a position engaging the flexible belts in the discharge conveying means Wit-h the image bearing surface of the sheet facing the louvered discharge of the duct structure connected to the air impelling means. The air discharged from this duct structure holds the sheet in engagement with the upwardly moving exible belts and thus detachably mounts the copy sheet on these belts for movement therewith. The air discharged from the duct structure not only mounts the developed copy sheet on the conveying belts but also provides a ow of air for removing any liquid remaining on the copy sheet. The upper end of the discharge conveying and drying means discharges the copy sheet with the image side up on the top Wall structure of the housing.

Many other objects and advantages of the present invention will become apparent from considering the following detailed description in conjunction with the drawings in which:

FIG. 1 is a perspective view of a photoelectrostatic copying apparatus embodying the present invention;

FIG. 2 is a sectional View taken generally along line 2 2 in FIG. 1;

FIG. 3 is an enlarged sectional view illustrating an optical system and adjusting means therefor which are ineluded in the copying apparatus;

FIG. 4 is an enlarged fragmentary end elevational view in partial section illustrating the adjusting linkage for the optical system;

FIG. 5 is an enlarged fragmentary sectional view of a copy sheet feeding assembly included in the copying machine;

FIG. 6 is a fragmentary top elevational view o-f the copying apparatus illustrating an assembly for producing a controlled flow of air for controlling the transportation and drying of copy sheets in the apparatus; and

FIG. 7 is a schematic diagram of a circuit for controlling the operation of the copying machine.

Referring now more specifically to FIGS. 1 and 2 of the drawings, therein is illustrated a copying machine which is indicated generally as 10 and which embodies the present invention. The machine 10 includes a housing 12 having four threaded or adjustable feet 14 (FIG. 2) for mounting the machine 10 in a level position on a lsupporting bench, table, or desk 16. An illuminating station indicated generally as 18 is provided adjacent one end of the generally rectangular housing 12 and includes a plate 20 of glass or other light transmitting material which forms a part of a top wall structure 22 for the housing 12. The glass pane 20 is so positioned in the top wall 22 that its edge is coextensive with the left-hand (FIG. 2) vertical wall of the housing 12. This permits the original material to be copied by the machine 10 to comprise not only sheet material but also material from bound volumes, such as a page of a book 24, shown in FIG. 1. The |book 24 can be placed with its back along the edge formed by the glass pane 20 and the vertical wall of the housing 12 with the page to be copied overlying the glass pane 20 and with the remainder of the book extending vertically along the adjacent wall of the housing 12.

A light source included in the illuminating station 18 provides light which is reflected from the original at the station 18 and is transmitted through an optical system indicated generally as 24 (FIG. 2) to impinge on an electrophotostatic copy sheet 26 which is held in a stationary position at an exposing station indicated generally as 28 during the exposure operation. The optical system 24 can be adjusted to a plurality of different settings by a control assembly or linkage indicated generally as 30 (FIG. 3) to permit the machine 10 to provide copies on the copy sheet 26 of different sizes, e.g., full or reduced size. The assembly 30 is manually actuated by the operator at a position outside of the housing 12 and does not require factory adjustment in order to provide copies of different sizes. To provide means for supplying a copy sheet 26 at the exposing station 28, the machine 10 includes a magazine assembly indicated generally as 32 (FIG. 2) containing a stack 34 of individual copy sheets 26.

' When the machine 10 is placed in operation, a novel control means in the sheet feeding assembly 32 is actuated to feed a single sheet from the stack 34 over a paper guideway to a charging station indicated generally as 36. As the forward edge of the sheet 26 provided by the assembly 32 approaches the charging station 36, a switch 38 is operated to place the charging station 36 in operation so that the opposite sides of the copy sheet 26 are provided with uniform electrostatic charges. A first sheet conveying assembly, which is indicated generally as 40 and which is intermittently operated, advances a charged sheet received from the charging station 36 to a position disposed in a xed and predetermined exposure plane at the station 28. The copy sheet 26 is held in engagement with the conveying means 40 by an air flow assembly indicated generally as 42 (FIG. 6) including an air impelling means whose intake is placed in communication with the conveying means 40 to hold the copy sheet 26 on the conveying means by suction or negative pressure.

When the sheet 26 is advanced to a properposition in the fixed and predetermined exposure plane at the station 28 by the conveying means 40, the leading edge of the sheet engages an operator 44a on a switch 44 and operates this switch. When the switch 44 is operated, further movement of the sheet conveying means 40` is arrested, and the light source at the illuminating station 18 is momentarily energized to forward a light image through the optical system 24 to selectively discharge the exposed surface of the copy sheet 26 at the exposure station 28.

After a suitable time delay, the conveying means 40 is placed in operation so that the exposed copy sheet containing a latent electrostatic image is advanced to a developing station 46 of a liquid type in which electroscopic powder in a liquid carrier is placed in contact with the electrically charged surface of the copy sheet 26 to provide a visible image by the selective deposition or attraction of the electroscopic powder. The leading edge of the developed copy sheet is received on a discharge and drying conveying means indicated generally as 48 and is held in engagement therewith by the air discharged from the air impelling assembly 42. This flow of air not only holds the developedcopy sheet 26 on the conveying means 48 lbut also dries any residual liquid retained on this copy sheet. The dried and developed copy sheet 26 is discharged into a Sheet receiving receptacle 50 carried on and forming a part of the top wall structure 22 of the housing 12.

Referring now more specifically to the illuminating station, this station is disposed at the left end of the housing 12 (FIGS. l and 2) immediately adjacent the top wall structure 22 and includes the light transmitting member or glass pane 20. A flexible opaque cover 52 is pivotally mounted on the housing adjacent the rear wall to provide means for securing the original material to be copied in a uniplanar position adjacent the glass pane 20. To provide a light source at the illuminating station 18, a pair of lamps 54 (FIGS. 2-4) and cooperating reflectors 56 are provided adjacent the front .and rear walls of the housing 12. The lamps 54 and the corresponding reflectors 56 are so disposed as to direct light against the lower surface of the,glass pane 20 to provide a reected light image which is directed by the optical system 24 onto the exposed surface of the copy sheet 26 at the exposure station 28.

The optical system or assembly 24 (FIGS. 2 and 3) includes a reflecting or mirror means 58 which is mounted in an inclined position below the glass pane 20 in a position to direct light reflected from the original to a lens assembly 60 included in the optical system 24. The mirror means 58 is mounted on a supporting structure 62 which is secured at its base to a plate 64. Opposite ends of the plate 64 are secured to a pair of bushing or sleeve members 66 which are slidably mounted on a pair of rods 68 supported on the base of the housing 12l at spaced positions lby a pair of standards 70. The sleeves 66.to which the supporting structure for the reflecting means 58 is connected are slidably mounted on the rods 68 to permit the mirror or reilecting means 58 to be moved toward and away from the lens assembly 60.

The lensassembly 60 includes a plurality of lens elements 72 carried in a lens barrel 74 that is secured to a front wall 76 of an extensible bellows 78. The other end of the bellows 78 is secured to an apertured end member 80 which is secured to a dividing wall or partition 82 in the housing 12 in alignment with an opening therein which places the lens assembly 60 in communication with the exposure station 28.

The lens assembly 60 is also slidably supported on the housing 12 by means of a pair of spaced shafts or rods 84 which arerigidly secured at one end to the member 80. The front wall 76 of the bellows assembly is secured at its opposite edges to a pair of sleeves 86 which are slidably mounted on the rods 84. An apertured plate 88 secured to the front end of the rods 84 by a pair of nuts 89 provides a front stop for limiting movement to the left (FIG. 3) of the sleeves 86. By moving the sleeves 86 on the rods 84, the bellows 78 is expanded and contracted and the position of the lens barrel 74 relative to the exposure plane and the reflecting means or mirror 58 can be varied.

The linkage or control assembly 30 (FIGS. 3 and 4) provides means for Vchanging the size of the light image impinging on the copy sheet 26 at the exposure station 28 by adjusting the relative positions of the mirror 58 and the lens assembly 60. The control assembly 30 includes a manual operating arm or knob 90 slidably mounted in and extending through a slot 92 (FIGS. 1, 3, and 4) in a shelf 12a disposed at the front of the housing 12. The lower end of the knob structure 90 is connected to a pair of connected links 94 and 96, and the other end of the link 96 is pivotally connected to the upper end of an arm 98 whose lower end is rigidly secured to one end of a shaft 100. The shaft 100 is pivotally mounted in a U-shaped bracket 102 carried on an intermediate wall of the housing 12. The other end of the shaft 102 is -rigidly secured to the upper end of an arm 104, and the lower end of the arm 104 is provided with an elongated slot 106 in which is received a pin 108 secured to the adjacent sleeve 86. In this manner, the knob 90 is coupled to the sleeves 86 connected to the lens barrel 74.

The pin or shaft 108 is also received within an elongated slot 110 in the upper end of a lever 112. An intermediate portion of the lever 112 is pivotally mounted on a shaft 114 ca-rried on a U-shaped bracket 116 secured to the intermediate Wall of the housing 12. The lower end of the lever 112 is pivotally connected to one end of a link 118, the other end of which is pivotally connected to an upstanding arm or plate which is secured to the base plate 64. Thus, the knob 90 is also coupled to the support for the reflecting means or mirror 58.

When the control assembly is in the position shown in FIG. 1, the optical system 24 provides a 1:1 ratio between the size of the original to be copied and the image projected onto the copy sheet 26 in the exposure plane at the exposing station 28. In this setting, the control linkage 30 occupies the position shown in solid line in FIG. 3. When it is desired to produce a reduced size copy in 4vwhich the ratio of the area of the copy sheet to the image area of the original is, for instance, 11:14, the knob 90 is moved to the left (FIG. 3) to pivot the arm 98 in a counterclockwise direction to the position shown in dashed line. This rotates the shaft 100 in a counterclockwise direction and swings the arm 104 to the right. As the arm 104 moves to the right, the sleeves 86 are moved to the right on the rods 84 to the position shown in dashed outline, and the lens elements 72 in the lens barrel 74 are moved to the right or closer to the exposure plane.

When the sleeve 86 and the pin 108 are moved to the right by the arm 104, the lever 112 is pivoted in a clockwise direction (FIG. 3) about the shaft 114 so that the link 118 is moved to the left to move the supporting structure 62 for the mirror to the left. This increases the distance from the mirror to the lens elements 72 in the lens barrel 74. With the lens elements 72 now positioned more closely adjacent the plane of exposure at the station 28 and with the reflecting means 58 shifted in a direction parallel to the light transmitting pane 20 away from the lens assembly 60, the image applied to the copy sheet 26 at the exposure station 28 is reduced in size relative to the original graphic material at the illuminating station 18. Accordingly, by manually adjusting the knob 90 at a position outside of the housing 12, the copying machine can be easily adjusted to provide copies of various sizes relative to the original.

As set forth above, the sheet feeding assembly 32 (FIGS. 2 and 5) is operable to feed a single photoelectrostatic copying sheet 26 from the stack 34 thereof each time that a copy is to be produced by the machine 10. The sheet feeding assembly 32 can be of any suitable construction but preferably comprises one of the type shown and described in detail in `the copending application of John L. Tregay, Ser. No. 441,063, led Mar. 19, 1965, which application is assigned to the same assignee as the present application. As shown therein, the assembly 32 includes a sheet or stack supporting table 130 on which a pair of adjustably mounted side rails or edge guides 132 are mounted for movement to spaced positions determined by the width of the copy sheets 26 to be supplied to the machine 10. A pair of separator arms 134 connected at their -rear end to the bight portion of two U-shaped brackets 136 are pivotally mounted thereby on a transversely extending rod or shaft 138. The forward ends of the two separator arms 134 include a vertically extending portion 134e which provides a front stop for the stack 34 and a rearwardly projecting lip or separator portion 134b which is adapted to rest on the top sheet 26 in the stack 34 adjacent a corner thereof.

When the top sheet 26 is engaged and fed forwardly by suitable drive means, the forward corners of the top sheet 26 buckle slightly to permit the sheet to pass beyond the two separator elements 134 which are disposed immediately adjacent the side rails or edge guides 132. The leading edge of the sheet 26 fed from the stack 34 is -guided between a pair of feed rollers 140 and 142 which are driven by suitable means (not shown) so as to be rotated during the interval in which the first sheet conveying assembly 40 is in operation. The leading edge of the sheet 26 is guided to the nip between the rollers 140 and 142 by an 4upwardly inclined and somewhat centrally disposed guide portion 130e formed integral with the stack supporting table 130.

The sheet feeding assembly 32 includes new and improved means for controlling the movement of sheet engaging and driving means into intermittent engagement of the top sheet 26 in the stack 34 so that sheets can be fed from the assembly `32 at times determined by the operating cycle of the machine 10. To provide means for feeding a sheet from the assembly 32, a pair of friction wheels 144 are mounted in spaced apart positions on a shaft 146 which is rotatably mounted between two levers 148 spaced outwardly from the two sides of the sheet A feeding assembly 32. The two levers 148 are pivotally mounted on a shaft 150 intermediate its ends, the shaft 150 being provided with -a driven pulley 152 which is coupled by a flexible belt 154 to a pulley (not shown) rigidly secured to the shaft 146. The pulley 142 rotates the shaft 146 and the friction wheels 144 secured thereto in a -clockwise direction (FIG. 5) aboutthe axis of the shaft 146 to feed the sheets 26 to the left (FIG. 5) or to the right (FIG. 2).

The two levers 148 are normally pivoted in a counterclockwise direction (FIG. 5) about the shaft 150 to a normal position determined by a stop (not shown) to hold the friction wheels 144 out of engagement with the sheet 26 in the stack 34. To bias the levers or supporting arms 148 to this position, a rod 156 connected between ends of these two levers is connected to one end of a flexible connector 158. The flexible connector 158 passes around one of the two pulleys 160 rotatably mounted on a shaft 162 and is connected at its other end to a tension spring 164. The other end of the tension spring 164 is connected to a lead screw 166 threadedly mounted in a downwardly extending flange or wall 168`z on a supporting bracket 168 carried in a fixed position on the housing 12 of the machine 10. By rotating the lead screw 166 to move to the right, greater tension is applied to the levers 148 through flexible connector 158 and the tension spring 164. By rotating the lead screw 166 to move to the left (FIG. 5), the bias applied by the spring 164 is reduced.

To provide means for selectively moving the friction wheels 144 into engagement with the top sheet 26 in the stack 34, the two levers or supporting arms 148 are connected by a rod 170 at a point disposed on the other side or to the right (FIG. 5) of the pivotal axis defined by the shaft 150. A flexible connector 172 is connected at one end to the rod 170 and passes around the second one of the pulleys 160 rotatably mounted on the shaft 162 to be secured at its other end to one end of a tension spring 174. The other end of the tension spring 174 is connected to the outer end of a magnetic armature 176 which is mounted for reciprocating motion within an axial opening in a winding in an electrical solenoid indicated generally as 178. A stop nut is threadedly mounted on the magnetic armature 176.

When the solenoid 178 is energized, the armature 176 moves to the right and applies a resilient bias to the spring 174 and the flexible connector 172 tending to pivot the levers or arms 148 in a clockwise direction about the shaft 150. The force provided by the operation of the solenoid 178 is sufficient to overcome the resilient bias provided by the spring 164 so that the arms 148 pivot in a clockwise direction to move wheels 144 into engagement with the top sheet 26 in the stack 34. Since this deflecting force is applied to the arms 148 through the tension spring 174, the wheels 144 are resiliently biased into engagement with the top sheet 26, and the same stroke of the armature 176 can cause movement of the arms 148 through dilfercnt distances in a clockwise direction about the shaft 150 to compensate for stacks 34 of varying heights. The stroke of the armature 176 can be adjusted by threading the stop nut 180 to various positions. When the solenoid 178 is released, the tension spring 164 pivots the arms 148 in a counterclockwise direction about the axis of the shaft 150 to move the friction wheels 144 out of engagement with the stack 34. It is only necessary for the friction wheels 144 to engage and drive the top sheet 26 of the stack 34 until the leading edge of the separated sheet 26 is received in the nip between the driven rollers 140 and 142.

As illustrated in FIG. 2 of the drawings, the sheet feeding and separating assembly 32 extendings in a generally horizontal direction interposed between the illuminating station 18, on the left, and the charging station 36 and the exposure station 28, on the right, in a position closely underlying the top wall structure 22. To permit the insertion of a stack 34 of copy sheets 26 between the side rails 132 in the assembly 32, the top wall structure includes a removable or hinged cover 182. Suitable means are provided which are accessible when the cover 182 is removed or displaced for lifting the separator arms 134 to permit the insertion of a new stack 34 under the rearwardly projecting portions 13411 on these separator arms. A switch 184 which is operated when the cover 182 is removed disables -certain components of the machine 10 to prevent its operation when the cover is not in place. A switch 186 in the assembly 32 is operated when the supply of copy sheets 26 has been depleted and is used to arrest operation of the machine 10 when this occurs.

The separated sheet 26 from the feeding assembly 22 enters the nip between the rollers 140 and 142 and moves in a generally horizontal direction (FIG. 2) to enter a guideway formed by a pair of arcuate or generally semicircular members 190 defining a passageway for directing the leading edge of the copy sheet downwardly toward the charging station 36. During movement through the passageway formed by the guideways 190, the leading edge of the sheet 26 engages and displaces an actuator arm 38a for the switch means 38 so that this switch is operated to energize the charging station 36.

This charging station applies a uniform electrostatic charge of `opposite polarity to opposite surfaces of the sheet 26. The charging station 36 includes a housing 192 having a centrally disposed passageway extending in a generally vertical direction. Supporting structures 194 on opposite sides of the passageway support corona discharge wires or other suitable means for imparting uniform electrostatic charge blankets to the opposite sides of the copy sheet 26 as it passes through the charging station 3'6. As the leading edge of the copy sheet 26 leaves the housing 192, it is placed in engagement with the lirst sheet conveying means 40 in the exposure station 28 to be moved to a position for exposure in which the uniform electrostatic charge on one surface of the sheet is selectively dissipated in accordance with the light image provided by the Optical system 24.

The rst sheet conveying means includes a plurality of ilexible belts 196 disposed in side-by-side spaced positions and carried on three lines of guide rollers or pulleys 198, 200, and 202. A drive motor 204 is coupled by flexible drive means 206 to one line of the rollers, such as the rollers 202. The direction of rotation of the driven line of rollers 202 is such that the flexible belts 196 move downwardly in the exposure plane and move upwardly in a position disposed to the rear or the right of the exposure plane.

To provide means for retaining the copy sheet 26 in engagement with the flexible belts 196 Without requiring the provision of opposing structures which would interfere with the transmisison of the light image to the copy sheet 26, a duct structure or plenum chamber 208 (FIGS. 2 and 6) is provided which is disposed between the different flights of the flexible belts 19'6. A forward or left-hand wall 208:1 of the duct structure or plenum chamber is provided with apertures placing the interior of this ch-amber in communication with the interior of the housing 12 immediately adjacent the belts 196. I-f desired, the belts 196 can be provided with perforations which are aligned with the openings in the walls 208. The opposite ends of the duct or plenum chamber 208 are placed in communication with the air intakes to a pair of blowers or air impelling means 210 and 212 disposed generally adjacent the front and back walls of the housing 12. The air impelling means 210 and 212 can comprise squirrel cage type exhaust blowers.

The air drawn from the interior of the housing 12 into the duct structure 208 provides a pressure differential across the belts 196 and the superimposed copy sheet 26 to detachably retain this sheet in engagement with the belt-s .196 for movement therewith. Accordingly, as the leading edge of the sheet 26 passes out of the exit of the charging station 3'6, it is fed between the belts 196 and a roller 214 (FIG. 2) and is then held in engagement with the belts 196 during their downward movement. When the trailing edge of Ithe copy sheet 26 passes beyond the operator 38a, the switch 38 is released. The drive motor 204 continues in operation until the leading edge of the sheet 26 on the conveying belts 196 engages and actuates the operator arm 44a for the switch means 44. The operation of the switch means 44 interrupts the operation of the motor 204 so that the charged -copy sheet 26 is retained in the exposure plane 4at the station 28 in a position to receive the light image supplied from the illuminating station 18 through the optical system 24. After a suitable delay, operation of the motor 204 is initiated, and the leading edge of the exposed sheet 2'6 passes between a roller 216 and 10 the belts 196 to be discharged to the developing station 46.

The developing station 46 can be of any suitable type well known in the industry, such as a magnetic brush or cascade developer using electroscopic or toner powder. In the illustrated copying machine 10, the developing station 46 utilizes a liquid developing technique and comprises a tank or reservoir 218 having mounted therein a pair of spaced and somewhat arcuately formed plates 220 dening a passageway having an inlet disposed immediately below the discharge end of the conveying means 40 and an exit or outlet disposed immediately below the inlet to the drying and discharge conveying means 48. The interior of the reservoir or vessel 218 is lled with a suitable liquid developer such as a mixture of electroscopic powder land a liquid vehicle. This liquid developer can, for instance, be of the type described in detail in U.'S. Patent No. 2,907,674. The lower guide structure 220 is provided with a plurality of spaced apertures 220a to permit the liquid developer solution to enter the passageway defined by the gui-de elements 220.

When the uniformly charged outer surface of the copy sheet 26 at the exposure station 28 is exposed in accordance with the light image provided by the optical system 24, this surface is selectively discharged to provide a latent electrostatic image which is developed at the developing station 4'6 by the selective deposition, attraction, or adherence of particles of electroscopic or toner powder from the liquid developer to the selectively charged surface of the sheet. This means that after a period of use', the concentration of the electroscopic powder or particles in the liquid developer becomes depleted and necessitates the replacement of this material. To accomplish this, the copying machine 10 includes a unit 219 for metering the liquid concentrate or slurry of electroscopic powder from a bulk supply thereof to the liquid developer unit. The unit 219 includes a vessel or reservoir tank tilled with a liquid developer of the same concentration as in the developer tank 220. The un-t 219 also includes a replaceable bottle or other container of the liquid concentrate which has a much higher percentage of the developer powder together with electrically operated or controlled dispensing means for feeding metered amounts of the concentrate to the reservoir tank portion of the unit 219. The electrically controlled dispensing means in the unit 219 can be of any suitable known construction. The unit 219 meters a quantity of the toner concentrate or slurry in response to the length of copy sheet material passed through the machine 10. Manually controlled means for operating the dispensing means can also be provided.

As illustrated in FIG. 2 of the drawings, the unit 219 is connected to the interior of the vessel 218 through a pair of lines 219a and 219b. A pumping means 221 is disposed in the line 219a to circulate the liquid developer replenished With concentrate between the unit 219 and the vessel 218. This circulation aids in equally distributing the electroscopic powder in the liquid developer serving to agitate the mixture and prevent the electroscopic powder from settling. The lines 219:1 and 219b preferably are provided in positions communicating with the interior of the vessel 218 at spaced apart locations to insure the adequate distribution of a liquid developer of uniform concentration throughout the interior of the vessel.

The machine 10 also includes means for detecting when the level of the liquid developer within the tank 218 falls below a level at which proper developing takes place. More specifically, a oat controlled valve 223 of any of the well known constructions is provided which is actuated whenever the level of liquid developer within the vessel 218 falls eblow the minimum level required for proper development of the exposed copy sheets 26.

When the leading edge of the exposed copy sheet 26 is fed past the idler or guide roller 216 into the entrance of the passageway defined by the guide members 220, this sheet is fed beneath the surface of the liquid developer and passed through the passageway propelled by the first transport means 40. A leading edge of the sheet leaves the developing passageway in the reservoir 218 through the exit or outlet opening and is fed into the nip between a pair of continuously driven rollers 222 and 224. Further movement of the developed sheet 26 is controlled by the discharge and drying conveying means 48.

The discharge and drying conveying means 48 includes a plurality of llexible belts 226 passing around a plurality of spaced lines of pulleys or rollers 228, 230, 232, and 234. A selected one of the lines of the pulleys, such as the line of pulleys 234, is coupled to a continuously operating drive motor 236 by flexible coupling or connecting means 238. The drive motor 236 can also be coupled to drive one of the rollers 222 and 224. The direction of rotation of the drive motor 236 is such that the right-hand portions of the flexible belts 226 are driven vertically upward.

To provide means for concurrently mounting the developed sheet 26 on the flexible belts 226 and to provide means for drying any liquid retained on the copy sheet, a duct structure or chamber 240 (FIGS. 2 and 6) is provided having a plurality of louver-type openings 242 therein. The louvered openings 242 are spaced from and directed toward the adjacent portion of the flexible belts 226. The duct or chamber 240 is coupled to the air discharge or outlet from the impelling means 210 and 212 so that the air discharged by these impelling means is directed against the flexible belts 226. Thus, as the leading edge of the developed copy sheet is discharged from between the rollers 222 and 224, the air blast forces this sheet against the llexible belts 226 to move therewith with the image bearing surface facing toward the duct structure 240. The flow of air directed out of the louvered openings 242 also dries the sheet 26. Thus, the air impelling means 210 and 212 serve to hold the copy sheet 26 in the exposure station 28 in position on the first conveying means 40 by suction and serve to dry and hold the developed copy sheet 26 on the flexible belts 226 in the conveying means 48 by a positive pressure.

As the leading edge of the developed copy sheet 26 passes beyond the upper end of the duct or chamber 240, the image is in a fixed or permanent state in which it is not distorted. The leading edge then passes between the flexible belts 226 and an additional set of flexible belts 244 which pass around a plurality of lines of rollers or pulleys 246, 248, and 250 and which are driven in synchronism with the belts 226. When the leading edge of the copy sheet 26 reaches the upper end of the housing 12, it is discharged from between the belts 226 and 244 into the print or copy receiving tray 50 with the developed and fixed image facing upwardly to permit immediate visual inspection without requiring the sheet to be inverted. The upper portion of the conveying means 48 including the lines of rollers 228, 246, and 248 and the upper portions of the flexible belts 226 and 244 is enclosed in an upwardly projecting housing 251 having an opening in its left-hand wall through which the developed copy sheets 26 are discharged to the copy receiving tray or receptacle 50.

A control circuit 260 (FIG. 7) coordinates and controls the operation of the various components of the copying machine 10. The machine 10 is placed in condition for operation by removing the cover 182 and placing a stack 34 of copy sheets 26 in the sheet feeding assembly 32. With the cover 182 replaced and a stack 34 of sheets 26 on the table 130, both the sheet detecting switch 186 and the cover control switch 184 are operated to their normal conditions. In the normal condition of the switch 186, a pair of contacts 18611 (FIG. 7) are closed, and a pair of contacts 186b are opened. The switch 184 (FIG. 7) is operated from the position shown to a closed position when the cover 182 is closed. The machine 10 is then prepared for operation by closing a main switch 262 to supply conventional alternating current potential to the control circuit 260. This potential is applied through the closed switch 184 to the winding of the developer pump 221 so that the liquid developer is circulated within the vessel 218. The input potential is also applied through the closed switch 184 to the winding of the motor 236 so that the discharge and drying conveying means 48 is placed in operation. This input potential is directly forwarded to the two air impelling means or blowers 2,10 and 212 so that a llow of air is produced through the ducts 208 and 240 to condition the conveying means 40 and 48 for operation. The input potential is also forwarded through a pair of normally closed contacts 264b on a relay 264 to energize the drive motor 204 so that the flexible belts 196 in the sheet conveying means 40 are advanced and the rollers 140 and 142 are placed in rotation.

If the supply of liquid developer in the tank 218 is at a high enough level to permit proper development of an exposed copy sheet 26, the level or lloat controlled switch 223 is in the operated condition shown as a closed pair of contacts in FIG. 7 of the drawings. The input potential is supplied through the contacts 223 across an operatingl winding 266 to operate this relay to close a pair of con- -tacts 266a and to open a pair of contacts 266b. The closed contacts 266a connect the input potential through the closed contacts 186a to the input of a full wave rectifier bridge 267, 'thereby providing a direct current operating potential for a number of components of the control circuit 260. The control circuit 260 remains in this condition until the copying machine 10 is started.

When a copy is to be' made of an original, such as a page from the book 24, the page to be copied is placed on the light transmitting pane 20, and the knob 90 is adjusted to its left-hand or right-hand position (FIG. l) in accordance with the size of the copy to be reproduced. The adjust-ment of the knob 90 controls the `assembly 30' `to place the reliecting means or mirror 58 and the lens assembly 60 in a correct position for producing the desired copy. The operator then adjusts an automatic counting control assembly or unit 268 to a setting representing the desired number of copies. The control unit 268 includes a manual operating knob 270 (FIGS. 1 and 6) mounted on the shelf 12a on the housing 12. The unit 268 is of a conventional construction and includes a pair of normally open contacts 268a (FIG. 7) which are closed when the knob 270 is yturned to a setting representing a desired number of copies. The setting of the knob 270 also advances a counting mechanism whose setting represents the desired number of copies. This counting mechanism is operated a single step in a direction toward a normal setting by a pawl and ratchet mechanism or other suitable means each time that a solenoid 26811 is energized. Accordingly, when the knob 270 is turned to a -setting representing the desired number of copies to be made from the original, the contacts 268/z are closed to initiate the cyclic operation of the lmachine 10 under the control of the control circuit 260. j

When the contacts 268a are closed, the operating winding of the solenoid 178 is connected across the output of the `bridge 267 and normally closed contacts 28% of relay 280, in a time delay circuit 272. When the solenoid 178 is operated, the armature 176 is retracted to pivot Vthe levers 148 in a clockwise (FIG. 5) or counterclockwise (FIG. 2) direction about shaft 150. The continuously drive rollers 144 move into engagement with the top copy sheet 26 disposed in the sheet feeding assembly 32.

This moves the top sheet 26 to the right (FIG. 2) into the nip between the rollers and 142, which are rotated by the energized motor 204. The rollers 140 and 142 advance the leading edge of the copy sheet 26 `through the guideway provided by the structures until the leading edge of the sheet 26 engages and deflects the operator 38a for the switch 38. When the switch 38 is operated, a pair of contacts 38b (FIG. 7) are closed.

The closure of the contacts 38b completes an energizing circuit for a timing motor 282 in the toner dispensing assembly 219 so tha-t a cam mechanism shown schematically at 282a is driven. After a period of time determined by the period that the contacts 38b are maintained in a closed condition, the cam means 282a closes la pair of normally open contacts 282b to connect a solenoid 284 across the output of the bridge 267. When 4the solenoid 284 is energized, a predetermined quantity of the toner concentrate is dispensed into the liquid developer in the unit 219. This energization of the solenoid 284 can also ibe controlled by a lmanually actuated switch 286. The contacts 282b are closed in a random time sequence relative to the feeding of the copy sheets 26 independence on the linear length of copy sheet exposed by Ithe machine 10. In other words, the contacts 28219 may or may not be closed during any given copy feeding operation and at random times during the copying cycle. The con-tacts 282b are opened by the cam means 282a in response to continuing operation of the timer motor 282.

The closure of the contacts 38b also connects the time delay circuit 272 across the input potential so that the winding of the relay 280 is energized and a capacitor 278 is charged `by pulsating half cycle signals supplied through a resistor 274 and a diode 2'76. The energization of the Winding of the relay 280 operates this relay to open the contacts 280b and to close a pair of normally open con- -tacts 28011. The closure of the contacts 280e connects the alternating current input potential to a power supply 288 forming la part of the charging station 36 so that a pair of corona discharge wires 290 and 292 for applying oppositely poled charges Ito the opposite sides of the copy sheet 26 are supplied wi-th direct current potentials. Thus, the charging station 36 is now placed in operation to apply uniform electrostatic charges of opposite polarity to the opposite sides of the copy sheet 26 as it passes through the charging station 36. The opening of the contacts 280b interrupts the above-described circuit for energizing the winding in the solenoid 178, and the tension spring 164 pivots the levers 148 in a clockwise direction (FIG. 2) to move the friction wheels 144 out of engagement with the stack 34. The copy sheet 26 previously separated from the stack 34 is propelled through the charging station 36 toward the exposure station 28 lby the rollers 140 and 142.

As the leading edge of the charged copy sheet 26 emerges from the housing 192 of the charging station 36, it passes between the pressure lroller 214 and the flexible belts 196 of the sheet conveying means 40` to be advanced to a position at which it is under the inuence of the air intake to the blowers or air i-mpelling means 210 and 212. Thus, the sheet 26 is held `in engagement and for movement with Ithe bel-ts 196 by the negative pressure or suction resulting from the air intake to the blowers 210 and 212. The sheet 26 moves downwardly in a generallyfvertical direction with the belts 196 in the sheet conveying means.

As the trailing edge of the copy sheet 26 passes the operator arm 38a for the switch 38, this switch is released to open the contact 38h. This terminates the energization of the timer motor 282. The opening of the contacts 38b also interrupts the energizing circuit for the winding of the'relay 280. However, this relay does not release at this time because of the time delay afforded by the charged capacitor 278 which now -discharges through the winding of the relay 280 to maintain this relay in an operated condition. The time delay provided -by the circuit 272 is such that the contacts 280a 'remain energized to maintain the energization of the power lsupply 288 until the trailing edge of the copy sheet 26 has been discharged from the charging station 36. This insures that the corona discharge wires 290 and 292 remain energized long enough to completely charge both surfaces of the copy sheet 26. This delay in the release of the relay 280 also maintains the contacts 280b in an open condition so that the copy feed solenoid 178 cannot Ibe operated.

When the charged sheet 26 is disposed in the exposure plane, its leading edge engages the operator 44a (FIG. 2) for the switch 44 and operates this switch to close a pair of normally open contacts 44h. When the contacts 44b (FIG. 7) yare closed, a timing unit 294 is rendered operative to control the illumination of the original at the illuminating station 18 and to momentarily arrest operation of the sheet conveying means 40. More specifically, when the contact-s 44b are closed, a timing motor 296 is placed in operation, and the relay 264 is connected across the input yalternating current potential over a circuit including a pair of normally closed contacts 296a controlled by the timer motor 296. The time of exposure of the copy sheet to the projected light image is Iselected by turning a contro-l knob 297 (FIG. 1) which positions the timing motor operated cam 296 with respect to the switch 296a. TIhe completion of the circuit including the closed contacts 29611 operate the relay 264 to close a plurality of contacts 264er' and 264e and to open the contacts 264b.

The opening of the contacts 264b interrupts the energizing circuit for the drive motor 204 so that the rollers and 142 are no longer driven and so that the exible belts 146 remain in a fixed position. In this position, the air passing through the duct structure 208- holds the charged copy sheet 26 in a xed exposure plane at the exposing station 28. The closure of the contacts 264C connects the lamps 54 across the input potential so that the original disposed on the light transmitting pane 20 at the illuminating station 18 is illuminated, and t-he light selectively reliected therefrom is transmitted over the optical system 24 to selectively discharge the uniformly charged surface of the copy sheet 26 at the exposing station to provide a latent electrostatic image corresponding to the original to be copied. The closure of the contacts 264e` also energizes -an operating winding in a counter 298 so that this counter is operated to add an increment of value indicating the production of a copy by the machine 10.

When the contacts 264a are closed by the operation of the relay 264, the `solenoid 268b in the counting control unit 268 is connected to the open contacts 280b on the relay 280 in the time delay unit 272. Thus, when the contacts 280b are closed at the end of the delay period of the unit 272, the solenoid 268b is energized to return the counting mechanism a single step in the direction of the normal setting of this unit. If only a single copy was requested, the unit 268 is returned to its normal position by the single operating pulse, and the contacts 268:1 are opened. This interrupts the operating circuits for the solenoid 268b and also interrupts the operating circuit for the copy feed solenoid 178 which was also completed by the closure of the contacts 280b. This momentary energization of the solenoid 178 may result in partial feeding of `a sheet 26 from the stack 34, but this does not affect the operation of the copying machine 10 inasmuch as it has not been fed a suicient distance to be received between the rollers 140` and 142.

At the end of the exposure step controlled by the exposure timer 294 as selected -by turning knob 297, the contacts 296a are opened to interrupt the operating circuit lfor the relay 264 so that the contacts 264a and 264C are opened and so that the contacts 264b are closed. The opening of the contacts 264a interrupts one point in the operating circuit for the solenoid 268b, and the opening of the contacts 264C terminates the energization of the lamps 54 and releases the counter 298. The closure of the contacts 264b completes the energizing circuit for the drive motor 204 so that this motor places the sheet conveying means 40 in operation and also initiates the rotation of the rollers 140- and 142. The rollers 140 and 142 will feed a copy sheet 26 from the assembly 32 if more than a single copy has been requested. When the conveying means 40 is placed in operation, the exposed copy sheet 26 at the station 28 is fed past the roller 216 into the guideway formed by the structures 220 within the tank 218 lat the developing station 46. The selectively discharged surface containing the latent electrostatic image is disposed face down within the liquid developer so that the electroscopic powder lfrom the developer is selectively deposited on the. surface to convert the latent electrostatic image into a visible image. When the leading edge of the developed copy sheet leaves the guideway provided by the structure 220, it `is received within the nip between the rollers 222 and 224 to Ebe fed to a position in which the back surface of the copy sheet 26 engages the flexible belts 226 with the developed surface facing the louvered openings 242 in the duct structure 240.

When the trailing edge of the copy sheet 26 moves beyond the operator 44a for the switch 44, this switch is released to open the contacts 44h. This terminates the energization of the timing motor 296 in the unit 294 and permits the contacts 296:1 to return to a closed condition to partially prepare the control circuit 260 for an additional cycle of operation.

When the leading edge of the developed copy sheet is fed by the rollers 222 and 224 onto the liexible belts 226 in the discharge and drying conveying means 40, the air discharged from the `duct 240 through the openings 242 not only forces the sheet against the belts 226e to move therewith but also dries the copy sheet. The de- -veloped copy sheet 26 is advanced by the belts 226 past the duct structure 240 so that the leading edge passes between the belts 226 and the belts 244. These two arrays of belts continue the generally vertical elevation of the developed copy sheet so that it is discharged from the housing 260 into the print-receiving tray or receptacle 50. Since the conveying means 48` operates continuously and since the energizing circuit for the solenoid 178 is completed as soon as the time delay unit 272 releases the relay 280, a subsequent copy sheet in multiple copy runs can be charged and exposed during the time interval in which the developed copy sheet is being discharged by the conveying means 48.

In the event that the supply of copy sheets 26 in the assembly 34 becomes depleted during the operation of the machine 10, the switch 186 is operated to open the contacts 186m and to close the contacts 18612. The closure of the contacts 186b illuminates a lamp 300` (FIGS. l, 6, and 7) to provide a visible indication that the supply of copy sheets 26 has been depleted. The opening of the contacts 186a interrupts the circuit for energizing the input of the rectifier bridge 267 so that the components energized by this bridge cannot be operated. Thus, further operation of the machine 10 is disabled whenever the supply of copy sheets 26 in the assembly 32 becomes depleted. Whenever the supply of copy sheets is replaced, the switch 186 is operated to open the contacts 186b and to close the contacts 186a to return the machine 10 to its normal condition.

Similarly, when the supply of liquid developer in the vessel or receptacle 218 `falls below the predetermined level necessary yfor properly developing exposed copy sheets, the oat controlled switch 223 is operated to interrupt the operating circuit for the relay 266. The release of the relay 266 opens the contacts 266a and closes a pair of contacts 266b. The clos-ure of the contacts 266b causes the il-lumination of a lamp 302 (FIGS. 1, 6, and 7) to provide a visible indication that it is necessary to provide additional liquid developer to the machine 10. The opening of the contacts 266:1 interrupts the input circuit to the rectifier bridge 2167 and disables the components energized thereby to prevent operation of the control circuit 260 and the machine 101. When the Supply of liquid developer is replenished so that the switch 223 is closed, the relay 266 is :again operated to restore the control circuit 260 to its normal condition.

Whenever the cover 182 is opened to replenish the supply of copy sheets 32, the switch 184 is opened. The opening of the switch 184 disables all of the components in the control circuit 260 with the exception of the blowers 210i. and 212 which are maintained in an energized condition over a circuit independent of the switch 184. Replacing the cover 182 closes t-he switch 184 so that the control circuit 260 is restored to its normal condition.

Although the present invention has been described wit reference to a single illustrative embodiment thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. An apparatus for making a copy of an original on a copy sheet comprising a housing having a generally uniplanar top wall structure, an illuminating station for illuminating the original and including a light transmitting member carried on and forming a part of the top wall structure of the housing, the light transmitting member being disposed at and forming an edge of the top wall surface and being adapted to support the original to be copied, a copy sheet exposing station disposed within the housing laterally spaced from the illuminating station, movably mounted optical means for projecting a light image from an illuminating station to said exposing station including means for adjusting said optical means to select the size of said image projected to said exposing station, automatic copy sheet feeding means, developing means for receiving an exposed copy sheet from the copy sheet exposing station and for developing the exposed copy sheet, rst intermittently operated conveyor means for conveying said sheet along a gener-ally vertical path -from said sheet feeding means to said developing means, means for locating said copy sheet at said exposure station along said vertical path, and second conveyor imeans operated independently of said first conveyor means for transporting a developed copy sheet through an opening in the top wall structure in a position spaced from the illuminating station to discharge the developed copy sheet in substantially the same plane as the original but laterally spaced therefrom across the top wall surface of the housing.

2. An apparatus for making a copy of an original on a copy sheet comprising a housing having a top wall structure, an illuminating station lfor illuminating the original and including a light transmitting member carried on and forming a part of the top wall structure of the housing, the light transmitting member being adapted to support the original to be copied in a generally horizontal plane, a copy sheet exposing station disposed within the housing laterally spaced from the illuminating station, said copy sheet exposing station including :a first intermittently operated conveyor means for supporting a copy sheet in a generally vertical position during exposure, movably mounted optical means for projecting a light image from said illuminating station to said exposing station including means for adjusting said optical means to select the size of said image projected to said exposing station, automatic copy sheet feeding means for supplying copy sheets to t-he copy sheet exposing station, developing means for receiving an exposed copy sheet from the copy sheet exposing station and for developing the exposed copy sheet, and second conveyor means operated independently of said rst conveyor means for discharging a developed copy sheet through an opening in the top wall structure spaced from the illuminating station, said second conveyor means moving `said copy sheet generally vertical toward the top wall structure.

3. The apparatus as claimed in claim 2 wherein said optical means includes a lens assembly and light reflecting means and a linkage coupled to the lens assembly and the light reflecting means and including manually operable control means outside of the housing for adjusting the lens assembly and the light reflecting means to different positions within the housing.

4. The apparatus as claimed in claim 3 wherein said light reflecting means is disposed at an angle relative to the plane of the illuminated original, means in said housing mounting the light reflecting means for movement in 17 a direction parallel to the plane of the original and said control means is coupled to the light reflecting means.

5. The apparatus as claimed in claim 2 including means for moving the lens assembly toward and away from the exposure plane, means in said housing for mounting the light reflecting means for movement in a direction parallel to the plane of the original and toward and away from the exposure plane, and control means coupled to the light reecting means and the lens assembly and including manual operable means for adjusting the light reflecting means to a position further away from the exposure plane while adjusting the lens assembly toward the exposure plane.

6. The apparat-us as claimed in claim 5 wherein said control means produces oppositely directed movement of the lens assembly and the light reecting means relative to the exposure plane.

7. An apparatus for making a copy of an original on a copy sheet comprising a housing having a top wall structure, an illuminating station for illuminating the original and including a light transmitting member carried on and forming a part of the top wall structure of the housing, the light transmitting member being adapted to support the original to be copied, a copy sheet exposing station disposed within the housing laterally spaced from the illuminating station, said copy sheet exposing station extending generally vertically within the housing and including a rst intermittently operated conveyor means for placing the copy sheet in a generally vertical position during exposure, movably mounted optical means for projecting a light image from said illuminating station to said exposing station including means for adjusting said optical means to select the size of said image projected to said exposing station, automatic copy sheet feeding'means for supplying copy sheets to the copy sheet exposing station, developing means disposed within the housing and having a copy sheet inlet disposed below the copy sheet exposing station for receiving an exposed copy sheet from the copy sheet exposing station, said developing means developing the exposed copy sheet and including .a developed copy sheet exit and second conveyor means operated independently of said rst conveyor for discharging a developed copy sheet through an opening in the top wall structure spaced from the illuminating station, said second conveyor means extending in a generally vertical direction and including means adjacent its lower end for receiving a developed copy sheet from the copy sheet exit.

8. The apparatus set forth in claim 7 including means for mounting the copy discharging means in a position adjacent the copy sheet exposing station and spaced on the oppmsite side of the copy sheet exposing station from the illuminating station.

9. An apparatus for making a copy of an original on a copy sheet comprising a housing having a top wall structure, an illuminating station for illuminating the original and including a light transmitting member carried on and forming a part of the top Wall structure of the housing, the light transmitting member being adapted to support the original to be copied, a copy sheet exposing station including intermittently operated first conveyor means disposed within the housing laterally spaced from the illuminating station, movably mounted optical means for projecting a light image from said illuminating station to said exposing station including means for adjusting said optical means to select the size of said image projected to said exposing station, automatic copy sheet feeding means for supplying copy sheets to the copy sheet exposing station, means mounting said copy sheet feeding means below the top wall structure in a position interposed between the illuminating station and the copy sheet exposing station and overlying the optical path, developing means for receiving an exposed copy sheet from the copy sheet exposing station and for developing the exposed copy sheet, and second conveyor means operated independently of said first conveyor means for discharging a developed copy sheet through an opening in the top wall structure spaced from the illuminating station.

10. The apparatus set forth in claim 9 in which the top Wall structure includes a movable wall section providing a cover overlying the copy feeding means.

11. An apparatus for making a copy of an original on a copy sheet comprising a housing having a top wall structure, an illuminating station for illuminating the original and including a light transmitting member carried on and forming a part of the top wall structure of the housing, the light transmitting member being adapted to support the original to be copied, a copy sheet exposing station disposed Within the housing laterally spaced from the illuminating station including intermittently operated first conveyor means, said copy sheet exposing station extending generally vertically within the housing and including means for placing the copy sheet in a generally vertical position during exposure, movably mounted optical means for projecting a light image from said illuminating station to said exposing station including means for adjusting said optical means to select the size of said image projected to said exposing station, automatic copy sheet feeding means for supplying copy sheets to the copy sheet exposing station, means mounting said copy sheet feeding means below the top wall structure in a generally horizontal position interposed between the illuminating station and the copy sheet exposing station and overlying the optical path, developing means disposed below the exposing station and including a copy sheet inlet for receiving an exposed copy sheet from the exposing station, said developing means also having a copy sheet exit, and second conveyor means extending generally vertically and operated independently of said first conveyor means for discharging a developed copy sheet from the housing upon receiving developed copy sheets from the copy sheet exit at its lower end.

12. The apparatus set forth in claim 11 in which the developing means includes a vessel for a developing liquid and in which the copy sheet inlet and exit are provided by laterally spaced and upwardly opening structures in the vessel.

13. An apparatus -for automatically making one or more copies of an original o-n a copy sheet comprising means for receiving an original to be copied, illuminating means yfor illuminating the original to be copied, copy sheet exposing means including a rst intermittently operable sheet conveying means, counting switch means preset to count the number of copies to be made, copy sheet feeding means responsive to said counting switch means for supplying a copy sheet to the copy sheet exposing means, developing means for receiving an exposed copy sheet from the exposing means, lirst control circuit means operative when a copy of an original is to be made for placing said first sheet conveying means in operation to advance a copy sheet supplied by the sheet feeding means to a predetermined position in the exposing means an-d for then arresting movement of said rst sheet conveying means to hold the copy sheet in a stationary position, second control means controlled by the first control means for operating the illuminating means to porduce a light image for exposing the stationary copy sheet, sensing switch means functioning in timed relation with the movement of the copy sheet into said exposure station for pulsing said counting switch means, third control means operative following the illumination of the original for again placing the sheet conveying means in operation to advance the exposed copy sheet into the developing means, said sheet feeding means being rendered inoperative when said preset count has been attained in said counting switch means, and second conveyor means operated independently of said first conveyor means for conveying the sheet from the developing means.

14. An apparatus for automatically making one or more copies of an original on a copy sheet comprising means for receiving an original to be copied, illuminating 1'9 means for illuminating the original-to be copied,rcopy sheet exposing means including a first intermittently operable sheet conveying means, counting switch means preset to count the number of copies to be made, copy sheet -feeding means responsive to said counting switch means for supplying a copy sheet to the copy sheet exposing means, developing means for receiving an exposed copy sheet from the exposing means, switch means disposed adjacent the path of movement of a copy sheet advanced by the sheet conveying means for pulsing said counting switch means and -operated when .the copy sheet is disposed in a predetermined exposure position within the exposing means, frst control circuit means controlled -by the switch means for arresting movement of said first sheet conveying means to hold the copy sheetina stationary position and for operating the illuminating means to pro duce a light image for exposing the stationary copy sheet, second control means operative following the illumination of the original for placing said first sheet conveying means in operation to advance the exposed copy sheet into the developing means, said sheet feeding means being rendered inoperative when said present count has been attained in said counting switch means, and second conveyor means operated independently of said rst conveyor means conveying the sheet from the developing means.

15. An appaartus for automatically making one or more copies original on a copy sheet comprising illuminating means for providing a light image of an original at a copy sheet exposing station, counting switch means to preset the number of copies to be made, copy sheet supplying means responsive to said counting switch means for supplying a copy sheet to the exposing station and including intermittently operable copy sheet conveying means, first control means responsive to movement of a copy sheet to the exposing station for momentarily arresting operation of the conveying means to supply a light image of the original to the copy sheet at the exposing station and pulsing said counting switch means, liquid developing means for receiving an exposed copy sheet from the exposing station and including a vessel containing a liquid ideveloper for producing a visible image on the exposed copy sheet, detecting means for determining the quantity of liquid developer in the liquid developing means, and second control means controlled by the detecting means for preventing operation of the copy sheet supplying means when the quantity of liquid developer in the liquid developing means is reduced below a pre-determined level, said sheet supplying means being rendered inoperative when said preset count has been attained in said counting switch means.

16. The apparatus set forth in claim 15 in which the liquid developer includes a liquid component and an electroscopic powder, dispensing means for periodically supplying a concentrated liquid `containing electroscopic powder to the liquid developer, the second control means preventing operation of the dispensing means when the quantity of liquid developer is reduced below a predetermined level.

17. An apparatus for automatically making one or more copies of an original on a copy sheet comprising illuminating means for providing a light image of the original at a copy sheet exposing station, counting switch means preset to count the number of copies to be made, copy sheet feeding means intermittently operable to feed copy sheets from a supply thereof, a Iirst intermittently operated sheet conveying means for receiving a copy sheet from the sheet feeding means and for moving the receive-d sheet to lthe exposing station, said first conveying means normally being operative, first control means responsive to the position of a copy sheet relative to the sheet conveying means for rendering the feeding means ineffective during the interval in which the copy sheet is moved over a given part of the path of movement of the sheet conveying means, developing means for receiving an exposed copy sheet from the exposing station, sec- `ond control means lincluding sensing switch means for closing said counting switch means responsive to movement of a copy sheet on the lirst conveying means to a given position in the exposing station for arresting movement of said first conveying means to hold the copy sheet in a stationary position and for rendering the illuminating means momentarily operative to expose the stationary copy sheet in accordance with the light image of the original, timing means for controllingthe time duration of said illuminating means, the second control means then placing said first conveying means in operation to feed the exposed copy sheet into the developing means, the rst control means being ineffective to place the sheet feeding means in operation to feed a sheet to the sheet conveying means until the sheet conveying means has been returned to operation to feed the exposed copy sheet to the developing means, said sheet feeding means being rendered inoperative when said preset count has been attained in said counting switch means, and second conveyor means operated independently of said first conveyor means for conveying the sheet from the developer means.

1S. An apparatus for automatically making one or more copies of an original on a copy sheet comprising illuminating means for providing a light image of the original at a copy sheet exposing station, counting switch means preset to count the number of copies to be made, copy sheet feeding means responsive to said counting switch means intermittently operable to feed copy sheets from a supply thereof, first inter-mittently operable sheet conveying means for receiving a copy sheet from the sheet feeding means and for moving the received sheet to the exposing station, charging means interposed in the path of movement of the copy sheet from the sheet feeding means to the copy sheet exposing station, first control means disposed in the path of movement of said copy sheet to energize said charging means and to render ineffective the feeding means, time delay means to keep said charging means energized after the tail portion of the copy sheet clears said first control means, second control means responsive to movement of a copy sheet on the sheet conveying means to a given position in the exposing station for arresting movement of said lirst conveying means to hold the copy sheet in a stationary position and Ifor rendering the illuminating means operative to expose the stationary copy sheet, switch means functioning in timed relation with the movement of the copy sheet into said exposure station for pulsing said cofunting switch means, timing means for controlling t-he time duration of said illuminating means, said second control means restoring said rst conveying means to operation at the conclusion of the exposure of the copy sheet, said sheet Ifeeding means being rendered inoperative when said preset count Ihas been attained in said counting switch means, and second conveyor means operated independently of said first conveyor means conveying the sheet from the developing means.

19. An apparatus for making a copy of an original on a copy sheet comprising a housing having a top wall structure, an illuminating station for illuminating the original and including a light transmitting member carried on and forming a part of the top wall stnuctfure of the housing, the light transmitting member being adapted to support the original to be copied, a copy sheet exposing station disposed Awithin 4a housing laterally spaced from the illuminating station, movably mounted optical means for projecting a light image from said illuminating station to said exposing station including means for adjusting said optical means to select the size of said image projected to said exposing station, automatic copy sheet feeding means, developing means disposed within said housing and having a copy sheet inlet disposed below the copy sheet exposing station, a rst intermittently operated belt conveyor means for conveying said copy sheet along a first generally vertical path from said sheet feeding means to said inlet, means for locating said copy sheet at said exposure station along said first path, said developing means developing the exposed copy sheet and including a developed copy sheet exit and a second copy conveying means operated independently of said rst conveying means for discharging a developed copy sheet through an opening in the top wall structure spaced from the illuminating station, said second copy conveying means extending in a .generally vertical direction lalong a second path and including means adjacent its lower end for receiving a developed copy sheet from the copy sheet exit.

References Cited UNITED STATES PATENTS 2,168,559 8/1939 Cernak 27156 3,135,180 6/1964 Cerasani 95--1.7 2,357,674 9/ 1944 McConnell 88--24 Schubert 88-24 Zollinger 88--24 Limberger 95-77.5 Keller 95-1.7 Alex-ander 95--1.7 Ritzerfeld 95-1.7

Young 95-1.7 Lud-wig 95--73 Cerasani 95-1.7 Sugarman 95-1.7 Rautbord 95-1.7

Stanton 95-1.7 Zerfahs 95-1.7 X

JOHN M. HORAN, Primary Examiner. 

